1. Field of the Invention
The present invention is directed to methods and materials for treating autoimmune and/or complement mediated diseases or conditions (in which complement involved either partly or predominantly in pathogenesis) and more particularly, to methods and materials for treating myasthenia gravis.
2. Description of the Related Art
Autoimmune diseases afflict large numbers of individuals in the U.S. and worldwide. For example, Myasthenia gravis (“MG”), an autoimmune neuromuscular disease, afflicts about 60,000 individuals in the United States and about 1,250,000 individuals worldwide. Neuromuscular transmission fails in MG because of decreased sensitivity of the postsynaptic membrane to the neurotransmitter acetylcholine (“ACh”), which results from a loss of acetylcholine receptors (“AChRs”) due to a T-cell and B-cell mediated autoimmune attack against the AChR (Christadoss et al., “Immunotherapy for Myasthenia Gravis: a Murine Model,” J. Immunol., 136(7):2437-2440 (1986)). Pemphigus, a group of autoimmune blistering diseases of the skin and/or mucous membranes, afflicts about 12,000 individuals in the United States and about 250,000 individuals worldwide. Autoimmune hemolytic anemia, a condition in which the immune system attacks the red blood cells, resulting in fewer of these oxygen-transporting cells, afflicts about 12,000 individuals in the United States and about 280,000 individuals worldwide. Idiopathic thrombocytopenic purpura, a bleeding disorder characterized by the destruction of platelets by the immune system, resulting in too few platelets in the blood, afflicts about 12,000 individuals in the United States and about 250,000 individuals worldwide. Autoimmune glomerulonephritis, a nephritis which is accompanied by inflammation of the capillary loops in the glomeruli of the kidney, afflicts about 60,000 individuals in the United States and over a million individuals worldwide.
Still other examples of autoimmune diseases that afflict large numbers of individuals in the U.S. and worldwide include Type I diabetes, rheumatoid arthritis, Hashimoto's disease, Graves disease, dermatomyositis, autoimmune vitiligo, psoriasis, and Guillain-Barre syndrome.
At present, many autoimmune diseases are treated using non-specific immunosuppressive drugs, such as steroids. However, steroids can have long-term side-effects, and they can suppress desirable immune responses. Non-steroidal immunosuppressive drugs have also been developed. For example, Eculizumab is a humanized monoclonal antibody that prevents the cleavage of human complement component C5 into pro-inflammatory components, and it has been approved to treat rheumatoid arthritis, nephritis, and phemphigus. However, use of this monoclonal antibody must be carefully monitored, as it can reduce a patient's ability to clear viruses, bacteria, and apoptotic and tumor cells, thus making patients more susceptible to bacterial and viral infection.
In view of the above, a need remains for methods and materials for treating autoimmune diseases. The present invention is directed, in part, to addressing this need.